Vapor-Liquid-Solid Growth of Si_1-xGe_x and Ge/Si_1-xGe_x Axial Heterostructured Nanowires

Abstract

The effect of growth conditions on the composition of Si1-xGex nanowires fabricated by vapor-liquid-solid growth using Si2H6 and GeH4 sources was investigated. The use of Si2H6 resulted in an increase in Si incorporation in the Si1-xGex nanowires at lower growth temperatures compared to SiH4 which is more commonly used. A wide range of Ge compositions from ~20-80% was achieved by changing the inlet gas ratio at a constant temperature in the range of 350-425ºC. Using these conditions, Ge/Si1-xGex axial heterostructured nanowires were also fabricated at 375ºC with Ge compositions of 92% and 66% in the SiGe segment and the morphology and interfacial compositional profile of the nanowires were examined.